A semi-finished blank for use in a varifocal liquid crystal lens is made up of a lower substrate whose surface has a convex curve, an upper substrate having a rear face with a concave curve that is joined to the upper face of the lower substrate face to face, and so forth. A varifocal component that is made up of a liquid crystal material is disposed between the upper and lower substrates. The refractive index of the varifocal component can be varied by applying voltage to the liquid crystal material. This semi-finished blank undergoes some processing and then is used as a lens for bifocal eyeglasses, for example (Patent Literature 1).